Relay switches



1958 s. F. PLAISANCE 2,8

RELAY SWITCHES Filed Oct. 1, 1953 IN VEN TOR.

Stanley F. Plaisance BY WM W United States Patent RELAY SWITCHES Stanley F. Plaisance, West Newton, Mass., assignor to Joseph Pollak Co oration, Dorchester, Mass, a corporation of Massac usetts Application October 1, 1953, Serial No. 383,583

6 Claims. (Cl. 317-198) The present invention relates to an improvement in relay switches wherein an electro-rnagnetically operated relay having a pivoted armature acts to close contact elements of a switch. Such type of relay controlled switches are used generally for commercial purposes in automobile and aircraft control devices and for other appliances in a great many arts.

Relays of the type herein described must give faithful and exact operation, be reliable and durable inasmuch as they are called upon to operate many thousands of times.

The present invention relates particularly to electromagnet relays in which the armature is supported by what may be called a bell crank lever, the other free arm of which is positioned to act against a spring switch for opening one circuit or opening one or more circuits and closing another. The relay switch of the present invention is so constructed that its pivoted armature will operate freely and smoothly for its entire life, it being in effect provided with a self-lubricating bearing.

Further an operating arm is controlled in such a manner that the operation will be definite and not provide transient effects such as chattering in the closing of the switch contacted by the operating harness or arm of the bell crank lever. The advantages of the present invention will be more readily appreciated from the description in the specification set forth below when in connection with the drawings illustrating an embodiment of the invention in which:

Figure 1 shows a side elevation of the invention with elements in fragmentary section.

Figure 2 shows a plan view looking down upon Figure 1.

In the arrangement indicated in Figures 1 and 2, the relay 1 comprises a coil 2 of conductive material with a central core 3 of magnetiza ble material. The core 3 may be contained within a spool on which the coil 2 is wound with covers or discs 4 and 5 through which the core 3 projects. The core 3, at its right end, has secured to it an inverted L-shaped bracket 6 by means of a bolt 7 and washer 8; the bolt passing through the bracket 6 and threading into the core 3, as shown by the dotted section 9, Figure l. The bracket 6 extends over the top of the discs 4 and 5 and coil 2 to the left hand end of the electromagnet as viewed in Figures 1 and 2. This bracket 6 in its top section 7 may be the full width or substantially the full width corresponding to the diameter of the coil 2. At the front end on the plate 7 of the bracket 6, there is mounted an assembly 10 comprising the bell crank lever 11 whose front face 12 or plate section is an armature which may be attracted by the core 3. The armature 12 is supported by two fork ends 13 and 14 through which a pin 15 extends which is secured in the fork ends 13 and 14 by making the ends of the pin 15 flat as indicated at 16 and 17.

There is wrapped around the pin 15 a thin sheet of Teflon 18 which is a polymerized tetra fiuoro ethylene. Some other equivalent synthetic plastic material having a finish characterized by the ethylene group which is ice durable, pliable yet very strong may also serve the same purpose, but I have found that Teflon is extremely satisfactory. This plastic sheet, which may be of the order of five to six thousandths of an inch in thickness, is wrapped around the pin 15 and is extended beneath the plate 19 which is semi-circular in shape and which lies over and against the top plate 7 of the bracket 6. Both ends of the sheet 18 are laid out flat under the plate 19 which is clamped in place by means of the clamping screw 20 beneath which there is a washer 21 with a small boss 22 extending into a recess or hole 23 in the plate 7. In this way, the sheet 18 is held securely in place. plate 19, at its other edge which roughly corresponds to the diameter of the semi-circular piece, is formed with a groove 24 by bending the outer surface 25 of the plate 19 in a semi-cylindrical convex arc with the underneath side open forming the grove which is used to hold the Teflon sheets wrapped around the pin 15 and securely in contact with it. By means of this construction, the Teflon sheet acts as a lubricant for the pivot or rod 15 and yet the sheet is so durable that it will last substantially indefinitely. By means of this arrangement, a freely pivoted bell crank lever is obtained which will have practically no frictional resistance in its motion.

Extending from one side of the assembly 10 isa small plate 26 which forms a part of and supports the arm 27 of the bell crank lever. This arm 27 has an upwardly turned finger 28 which rests under normal conditions upon an arm 35 of a fixed bracket which vw'll be described later and which when operated is made to bear against the spring contact finger 29 which is one of the contact springs of the switch element shown in Figures 1 and 2. Figures 1 and 2 show other contact elements 30 and 31 which extend in a general direction parallel with the contact spring 29. The members 30 and 31 may be heavier than the spring member 29 and may also be comparatively rigid if desired, so that they are not bent in a spring fashion. The finger 28 bears against the spring element 29 and when the coil of the relay is energized to attract the armature 12, the finger 28 lifts the spring 29 break-' ing the contact between bosses 32 and 33 and forming a new contact between the spring 29 and the upper contact 34 on the bar 31. Since the spring 29 may have considerable resilience when contact is made between the spring 29 and the upper bar 31, a reacting force may bounce the finger 28 downward causing a chattering in the closing of the contacts between the elements 29 and 30. This is prevented by the fixed arm or bar 35 which extends just below and comes in contact with the lower surface of the arm 27 of the bell crank lever. This bar or arm 35 is surrounded by a loosely fitting sleeve 36 of soft plastic material which may be polyethylene, styrene, nylon, or some other plastic capable of absorbing the vibration as the arm 27 may touch it so that there will be no rebounding of the arm 27 to cause either an opening between the contacts 32 and 33 or a closing of the switch arm 29 and the contact 34.

Having now described my invention, I claim:

1. In a relay switch of the type described having a relay coil and armature; means including said armature forming a bell crank lever in which said armature forms an arm on one side of the pivot of the lever with the other arm on the other side of the pivot, said pivot including a pivoted rod, a plastic sheet element having the surface characteristics of a smooth durable waxlike surface wrapped about said pivoting rod and providing a self lubricating bearing for the rod, and means securing said pivoting rod in its pivoting position within the plastic sheet.

2. In a relay switch of the type described; means pivoting an armature comprising a pivoting rod, a plastic sheet element having the surface characteristics of a The smooth durable waxlike surface wrapped about said pivoting rod and providing a self lubricating bearing for the rod, and means securing said pivoting rod in its pivoting position Within the plastic sheet.

3. In a relay switch of the type described having a relay coil; means pivoting an armature adjacent the coil comprising a forked member supporting said armature, a pivoting rod bridging said forked member, a plate element fixed at the side of said relay, a clamping plate in face to face position with said first mentioned plate having a groove in which said pivoting rod rests, a plastic sheet material wrapped about said rod providing a self lubricating bearing for the rod and having its ends lying between said plates, and means securing said plates together.

4. In a relay of the type described having a relay coil and pivotable armature; means pivotally supporting said armature comprising a forked member supporting said armature, a pivoting rod bridging said forked member, a plate element fixed at the side of said relay, a clamping plate in face to face position with said first mentioned plate having a groove in which said pivoting rod rests, a plastic sheet material wrapped about said rod providing a self lubricating bearing for the rod and having its ends lying between said plates and means clamping said plates together within the plastic sheet.

5. In a relay of the type described having an armature and coil; an armature bearing structure comprising a pivoting rod, means including a pair of plates positioned in face to face relation, a groove formed in one of the plates and receiving said rod, a sheet of plastic material wrapped about said rod with its free ends positioned between said plates, said sheetforming a self-lubricating bearing for the rod, and means clamping together said plates with the free ends of the material between them.

6. A device as described in claim 5, further characterized by the sheet being made of a polymerized tetrafluoroethylene.

References Cited in the file of this patent UNITED STATES PATENTS 1,179,194 Lane Apr. 11, 1916 1,651,684 Erickson Dec. 6, 1927 2,272,496 Wood Feb. 10, 1942 2,281,687 Fowler May 5, 1942 2,368,201 Clare Jan. 30, 1945 2,412,273 King Dec. 10, 1946 2,456,036 Wood Dec. 14, 1948 2,622,949 Cotchett Dec. 23, 1952 FOREIGN PATENTS 442,219 Canada June 17, 1947 

